Fracture fixation device, tools and methods

ABSTRACT

Bone fixation methods and devices with an elongate body having a longitudinal axis and having a flexible state and a rigid state, a plurality of grippers, a rigid hub connected to the elongated body, and an actuator operably connected to the grippers to deploy the grippers from a first shape to an expanded second shape. One method can include inserting a bone fixation device into an intramedullary space of the bone to place at least a portion of an elongate body of the fixation device in a flexible state on one side of the fracture and at least a portion of a rigid hub on another side of the fracture, and operating an actuator to deploy a plurality of grippers of the fixation device to engage an inner surface of the intramedullary space to anchor the fixation device to the bone.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. application Ser. No.13/032,437 filed on Feb. 22, 2011, which is a continuation of U.S.application Ser. No 11/944,366 filed Nov. 21, 2007, now U.S. Pat. No.7,909,825 issued on Mar. 22, 2011, which claims the benefit under 35U.S.C. §119 of the following U.S. Provisional Applications, thedisclosures of which are incorporated herein by reference: U.S.Application No. 60/867,011 filed Nov. 22, 2006; U.S. Ser. No. 60/866,976filed Nov. 22, 2006; and U.S. Application No. 60/949,071 filed Jul. 11,2007. Any and all priority claims identified in the Application DataSheet, or any correction thereto, are hereby incorporated by referenceunder 37 CFR 1.57.

All publications and patent applications mentioned in this specificationare herein incorporated by reference to the same extent as if eachindividual publication or patent application was specifically andindividually indicated to be incorporated by reference.

BACKGROUND

Embodiments of the present invention relate to methods and systems forproviding reinforcement of bones. More specifically, the presentinvention relates to methods and systems for providing reconstructivesurgical procedures and devices for reconstruction and reinforcementbones, including diseased, osteoporotic and fractured bones.

1. Field of the Invention

Bone fractures are a common medical condition both in the young and oldsegments of the population. However, with an increasingly agingpopulation, osteoporosis has become more of a significant medicalconcern in part due to the risk of osteoporotic fractures. Osteoporosisand osteoarthritis are among the most common conditions to affect themusculoskeletal system, as well as frequent causes of locomotor pain anddisability. Osteoporosis can occur in both human and animal subjects(e.g. horses). Osteoporosis (OP) and osteoarthritis (OA) occur in asubstantial portion of the human population over the age of fifty. TheNational Osteoporosis Foundation estimates that as many as 44 millionAmericans are affected by osteoporosis and low bone mass, leading tofractures in more than 300,000 people over the age of 65. In 1997 theestimated cost for osteoporosis related fractures was $13 billion. Thatfigure increased to $17 billion in 2002 and is projected to increase to$210-240 billion by 2040. Currently it is expected that one in twowomen, and one in four men, over the age of 50 will suffer anosteoporosis-related fracture. Osteoporosis is the most importantunderlying cause of fracture in the elderly. Also, sports andwork-related accidents account for a significant number of bonefractures seen in emergency rooms among all age groups.

2. Description of the Related Art

One current treatment of bone fractures includes surgically resettingthe fractured bone. After the surgical procedure, the fractured area ofthe body (i.e., where the fractured bone is located) is often placed inan external cast for an extended period of time to ensure that thefractured bone heals properly. This can take several months for the boneto heal and for the patient to remove the cast before resuming normalactivities.

In some instances, an intramedullary (IM) rod or nail is used to alignand stabilize the fracture. In that instance, a metal rod is placedinside a canal of a bone and fixed in place, typically at both ends.See, for example, Fixion™ IM (Nail), www.disc-o-tech.com. This approachrequires incision, access to the canal, and placement of the IM nail.The nail can be subsequently removed or left in place. A conventional IMnail procedure requires a similar, but possibly larger, opening to thespace, a long metallic nail being placed across the fracture, and eithersubsequent removal, and or when the nail is not removed, a long termimplant of the IM nail. The outer diameter of the IM nail must beselected for the minimum inside diameter of the space. Therefore,portions of the IM nail may not be in contact with the canal. Further,micro-motion between the bone and the IM nail may cause pain or necrosisof the bone. In still other cases, infection can occur. The IM nail maybe removed after the fracture has healed. This requires a subsequentsurgery with all of the complications and risks of a later intrusiveprocedure.

External fixation is another technique employed to repair fractures. Inthis approach, a rod may traverse the fracture site outside of theepidermis. The rod is attached to the bone with trans-dermal screws. Ifexternal fixation is used, the patient will have multiple incisions,screws, and trans-dermal infection paths. Furthermore, the externalfixation is cosmetically intrusive, bulky, and prone to painfulinadvertent manipulation by environmental conditions such as, forexample, bumping into objects and laying on the device.

Other concepts relating to bone repair are disclosed in, for example,U.S. Pat. No. 5,108,404 to Scholten for Surgical Protocol for Fixationof Bone Using Inflatable Device; U.S. Pat. No. 4,453,539 to Raftopouloset al. for Expandable Intramedullary Nail for the Fixation of BoneFractures; U.S. Pat. No. 4,854,312 to Raftopolous for Expanding Nail;U.S. Pat. No. 4,932,969 to Frey et al. for Joint Endoprosthesis; U.S.Pat. No. 5,571,189 to Kuslich for Expandable Fabric Implant forStabilizing the Spinal Motion Segment; U.S. Pat. No. 4,522,200 toStednitz for Adjustable Rod; U.S. Pat. No. 4,204,531 to Aginsky for Nailwith Expanding Mechanism; U.S. Pat. No. 5,480,400 to Berger for Methodand Device for Internal Fixation of Bone Fractures; U.S. Pat. No.5,102,413 to Poddar for Inflatable Bone Fixation Device; U.S. Pat. No.5,303,718 to Krajicek for Method and Device for the Osteosynthesis ofBones; U.S. Pat. No. 6,358,283 to Hogfors et al. for Implantable Devicefor Lengthening and Correcting Malpositions of Skeletal Bones; U.S. Pat.No. 6,127,597 to Beyar et al. for Systems for Percutaneous Bone andSpinal Stabilization, Fixation and Repair; U.S. Pat. No. 6,527,775 toWarburton for Interlocking Fixation Device for the Distal Radius; U.S.Patent Publication US2006/0084998 A1 to Levy et al. for ExpandableOrthopedic Device; and PCT Publication WO 2005/112804 A1 to MyersSurgical Solutions, LLC for Fracture Fixation and Site StabilizationSystem. Other fracture fixation devices, and tools for deployingfracture fixation devices, have been described in: US Patent Appl. Publ.No. 2006/0254950; U.S. Ser. No. 60/867,011 (filed Nov. 22, 2006); U.S.Ser. No. 60/866,976 (filed Nov. 22, 2006); and U.S. Ser. No. 60/866,920(filed Nov. 22, 2006).

In view of the foregoing, it would be desirable to have a device, systemand method for providing effective and minimally invasive bonereinforcement and fracture fixation to treat fractured or diseasedbones.

SUMMARY OF THE INVENTION

Aspects of the invention relate to embodiments of a bone fixation deviceand to methods for using such a device for repairing a bone fracture.The bone fixation device may include an elongate body with alongitudinal axis and having a flexible state and a rigid state. Thedevice further may include a plurality of grippers disposed atlongitudinally-spaced locations along the elongated body, a curved rigidhub connected to the elongated body, and an actuator that isoperably-connected to the grippers to deploy the grippers from a firstshape to an expanded second shape.

With regard to the actuator, in some embodiments of the bone fixationdevice, the actuator is operably connected to the elongate body in orderto change the elongate body from its flexible state (such as forinsertion into the bone through a curved access port) to its rigid state(such as to rigidly hold to the substantially straight bone shaft). Insome embodiments, the actuator is operably connected to a first gripperthat is disposed at the proximal end of the elongate body and to asecond gripper that is disposed at the distal end of the elongate bodyso as to be able to expand the first and second grippers simultaneously.

With further regard to the actuator of the device, the actuator mayinclude a ratchet that permits movement of the actuator only in adeployment direction, and in some of these embodiments, the device mayinclude a ratchet release. With still further regard to the actuator, insome embodiments the actuator may be threaded, and in some embodiments,the actuator may be rotatable with respect to the grippers.

With regard to the shape of the grippers of the device, in someembodiments, the second shape of at least one gripper is shorter alongthe longitudinal axis in its expanded second shape than it is in itsfirst shape.

With regard to one of the plurality of grippers of the device, in someembodiments a first gripper includes an element that pivots away fromlongitudinal axis of the elongated body when the first gripper isdeployed from the first shape to the second shape. In various of thesepivoting element-including embodiments, the first gripper may includetwo sets or three sets of oppositely disposed pivoting elements at thesame axial location of the elongate body, the pivoting elements beingadapted to pivot away from longitudinal axis of the elongated body whenthe first gripper is deployed from the first shape to the second shape.

In some of the embodiments with a gripper that includes a pivotingelement, a first gripper may include a pair of pivoting elementsdisposed on opposite sides of the elongate body at the same axialposition of the elongate body. In various of embodiments that include agripper with a pair of pivoting elements, the pair of pivoting elementsmay be connected to the elongate body so as to rotate either in the samedirection or in opposite directions when the first gripper is deployedfrom the first shape to the second shape. In some embodiments with agripper that includes a pivoting element, the element may include eitherone or two bone-engaging surfaces that pivot radially outward from theelongate body.

With regard to the curved hub of the device, in some embodiments, thecurved hub includes screw holes that may be pre-drilled and pre-tapped,and some embodiments the hub may include a drill alignment toolinterface to drill the screw holes during surgery.

With regard to a method for using embodiments of the bone fixationdevice, as summarized above, to repair a fractured bone, the methodincludes inserting a bone fixation device into an intramedullary spaceof the bone, placing at least a portion of an elongate body of thefixation device in a flexible state on one side of the fracture and atleast a portion of a curved rigid hub on another side of the fracture,and operating an actuator to deploy a plurality of grippers of thefixation device to engage an inner surface of the intramedullary spaceto anchor the fixation device to the bone.

In some method embodiments, the method further includes rigidizing theelongate body after the inserting step, and in some of theseembodiments, the rigidizing step includes operating the actuator.

With regard to the operating step of the method, some embodimentsinclude shortening one of the grippers.

With further regard to the operating step of the method, someembodiments include pivoting a pivotable gripper element away from thelongitudinal axis of the elongate body. In some embodiments, at leasttwo pivotable gripper elements are pivoted away from a longitudinal axisof the elongate body, the pivotable gripper elements being disposed atdifferent axial locations on the elongate body. In some embodiments, thepivoting step includes moving two bone engaging surfaces of thepivotable gripper element into engagement with the bone. In someembodiments of the method, the pivoting step includes moving either twoor three sets of pivotable gripper elements away from the longitudinalaxis of the elongate body, the two sets being disposed on opposite sidesof the elongate body at the same axial position. In some embodiments ofthe method, the pivoting step includes pivoting a pair of pivotingelements disposed on opposite sides of the elongate body at the sameaxial position so that two surfaces of each pivoting element engage theinner surface of the intramedullary space. In some embodiments of themethod, the pivoting step includes rotating the pivoting elements in thesame or in respectively opposite directions.

With still further regard to the operating step of the method and theactuator, some embodiments include moving the actuator longitudinallywith respect to the fixation device. In some of these embodiments, themethod further includes engaging a ratchet with the actuator to permitmovement of the actuator only in a deployment direction, and in some ofthese embodiments, the method may further include disengaging theratchet such as for removal of the device. With still further regard tothe method's operating step and the actuator, some embodiments mayinclude rotating the actuator with respect to the fixation device.

Some embodiments of the method further includes inserting a screwthrough the bone and the hub. These particular embodiments may furtherinclude forming a hole through the bone and the hub prior to insertingthe screw. In some embodiments that include the step of inserting ascrew through the bone and the hub, the step may include inserting afixation device having a curved hub with a preformed hole, the step ofinserting a screw by way of this embodiment thereby including insertinga screw through the bone and the preformed hole. In some of these latterembodiments, the curved hub has a plurality of preformed holes, themethod then including inserting a first screw dorsal to volar throughtwo portions of the bone and a first and second of the preformed holesand inserting a second screw volar to dorsal through two other portionsof the bone and a third and fourth of the preformed holes. In some ofthese latter embodiments, the method may further include inserting athird screw proximal to distal through two more portions of the bone anda fifth and sixth of the preformed holes of the hub. In still furtherembodiments of the method that include the step of inserting a screwthrough the bone and the hub, the method may further include attaching adrill alignment guide to the hub and aligning a drill bit with the hubusing the drill alignment guide.

One embodiment of the present invention provides a low weight to volumemechanical support for fixation, reinforcement and reconstruction ofbone or other regions of the musculo-skeletal system in both humans andanimals. The method of delivery of the device is another aspect of theinvention. The method of delivery of the device in accordance with thevarious embodiments of the invention reduces the trauma created duringsurgery, decreasing the risks associated with infection and therebydecreasing the recuperation time of the patient. The framework may inone embodiment include an expandable and contractible structure topermit re-placement and removal of the reinforcement structure orframework.

In accordance with the various embodiments of the present invention, themechanical supporting framework or device may be made from a variety ofmaterials such as metal, composite, plastic or amorphous materials,which include, but are not limited to, steel, stainless steel, cobaltchromium plated steel, titanium, nickel titanium alloy (nitinol),superelastic alloy, and polymethylmethacrylate (PMMA). The supportingframework or device may also include other polymeric materials that arebiocompatible and provide mechanical strength, that include polymericmaterial with ability to carry and delivery therapeutic agents, thatinclude bioabsorbable properties, as well as composite materials andcomposite materials of titanium and polyetheretherketone (PEEK™)composite materials of polymers and minerals, composite materials ofpolymers and glass fibers, composite materials of metal, polymer, andminerals.

Within the scope of the present invention, each of the aforementionedtypes of device may further be coated with proteins from synthetic oranimal source, or include collagen coated structures, and radioactive orbrachytherapy materials. Furthermore, the construction of the supportingframework or device may include radio-opaque markers or components thatassist in their location during and after placement in the bone or otherregion of the musculo-skeletal systems.

Further, the reinforcement device may, in one embodiment, be osteoincorporating, such that the reinforcement device may be integrated intothe bone.

In a further embodiment, there is provided a low weight to volumemechanical supporting framework or device deployed in conjunction withother suitable materials to form a composite structure in-situ. Examplesof such suitable materials may include, but are not limited to, bonecement, high density polyethylene, Kapton®, polyetheretherketone(PEEK™),and other engineering polymers.

Once deployed, the supporting framework or device may be electrically,thermally, or mechanically passive or active at the deployed site withinthe body. Thus, for example, where the supporting framework or deviceincludes nitinol, the shape of the device may be dynamically modifiedusing thermal, electrical or mechanical manipulation. For example, thenitinol device or supporting framework may be expanded or contractedonce deployed, to move the bone or other region of the musculo-skeletalsystem or area of the anatomy by using one or more of thermal,electrical or mechanical approaches.

An embodiment of the invention includes a lockable bone fixation devicecomprising: a rigidizable flexible body adapted to be positioned in aspace formed in a bone; a guide wire adapted to guide movement of thebody; and an actuable lock adapted to secure the body within the spaceof the bone from an end of the device. The body can be configured to beflexible, have apertures, be expandable and/or be bioabsorbable.Further, the body can be removable from the space within the bone, ifdesired. The device is adapted and configured to access the space withinthe bone through an access aperture formed in a bony protuberance of thebone. In a further embodiment, a second body can be provided that isadapted to fit within the first body. The anchors, e.g., teeth orinterdigitation process, are adapted to engage bone. In still anotherembodiment of the invention, a cantilever adapted to retain the lockablebone fixation device within the space. In still another embodiment, thedevice is adapted to be delivered by a catheter. In yet anotherembodiment, the distal end of the device is adapted to provide anobsturator surface. In still another embodiment of the device, thedistal end of the device is configured to provide a guiding tip. In yetanother embodiment of the device, the device is adapted to receiveexternal stimulation to provide therapy to the bone. In still anotherembodiment of the device, the device is adapted to receive compositematerial when the device is disposed within a lumen or opening withinthe body or bone.

In still another embodiment of the invention, a method of repairing abone fracture is disclosed that comprises: accessing a fracture along alength of a bone through a bony protuberance at an access point at anend of a bone; advancing a bone fixation device into a space through theaccess point at the end of the bone; bending a portion of the bonefixation device along its length to traverse the fracture; and lockingthe bone fixation device into place within the space of the bone. Themethod can also include the step of advancing an obsturator through thebony protuberance and across the fracture prior to advancing the bonefixation device into the space. In yet another embodiment of the method,the step of anchoring the bone fixation device within the space can beincluded. In still another embodiment of the method, a first sleeve anda second sleeve of the bone fixation device can be engaged to expand ananchor into the bone.

An aspect of the invention discloses a removable bone fixation devicethat uses a single port of insertion and has a single-end of remoteactuation wherein a bone fixation device stabilizes bone. The bonefixation device is adapted to provide a single end in one area orlocation where the device initiates interaction with bone. The devicecan be deployed such that the device interacts with bone. Single portalinsertion and single-end remote actuation enables the surgeon to insertand deploy the device, deactivate and remove the device, reduce bonefractures, displace bone, and lock the device in place. In addition, thesingle-end actuation enables the device to grip bone, compresses therigidizable flexible body, permits axial, torsional and angularadjustments to its position during surgery, and releases the device fromthe bone during its removal procedure. A removable extractor can beprovided in some embodiments of the device to enable the device to beplaced and extracted by deployment and remote actuation from a singleend. The device of the invention can be adapted and configured toprovide at least one rigidizable flexible body or sleeve. Further thebody can be configured to be flexible in all angles and directions. Theflexibility provided is in selective planes and angles in the Cartesian,polar, or cylindrical coordinate systems. Further, in some embodiments,the body is configured to have a remote actuation at a single end.Additionally, the body can be configured to have apertures, windings,etc. Another aspect of the invention includes a bone fixation device inthat has mechanical geometry that interacts with bone by a change in thesize of at least one dimension of a Cartesian, polar, or sphericalcoordinate system. Further, in some embodiments, bioabsorbable materialscan be used in conjunction with the devices, for example by providingspecific subcomponents of the device configured from bioabsorbablematerials. A sleeve can be provided in some embodiments where the sleeveis removable, has deployment, remote actuation, and a single end. Wherea sleeve is employed, the sleeve can be adapted to provide a deployableinterdigitation process or to provide an aperture along its lengththrough which the deployable interdigitation process is adapted toengage bone. In some embodiments, the deployable interdigitation processis further adapted to engage bone when actuated by the sleeve. In someembodiments, the bone fixation device further comprises a cantileveradapted to retain the deployable bone fixation device within the space.The sleeve can further be adapted to be expanded and collapsed withinthe space by a user. One end of the device can be configured to providea blunt obsturator surface adapted to advance into the bone. A guidingtip may also be provided that facilitates guiding the device through thebone. Further, the deployable bone fixation device can be adapted toreceive external stimulation to provide therapy to the bone. The devicecan further be adapted to provide an integral stimulator which providestherapy to the bone. In still other embodiments, the device can beadapted to receive deliver therapeutic stimulation to the bone.

The invention also includes a method for repairing a bone fracturecomprising: accessing a fracture along a length of bone through a bonyprotuberance at an entry portal; introducing the bone fixation deviceinto the medullary canal through the entry portal; bending the bonefixation device along its length to advance into the medullary space inthe bone; bending the bone fixation device along its length to traversethe fracture site; placing a flexible elbow in the medullary canal atthe fracture site; stiffening the bone fixation device; locking the bonefixation device to the bone; reducing the fracture with the bonefixation device in place in the medullary canal; locking the flexibleelbow to achieve intramedullary reduction of the fracture. The methodcan further include the step of introducing a guide wire into themedullary space through a bony protuberance at an entry portal.Additionally, the guide wire can be reamed through the bony protuberanceat an entry portal. The location of the reamed bony canal can bedetermined by the fracture anatomy and bone anatomy. In some embodimentsof the method, a sleeve can be advanced along the bone fixation device.In such embodiments, the sleeve can function to unlock the spikes fromthe fixation device. Once the spikes are unlocked from the fixationdevice, the spikes then fix the device to the bone. Locking rings canalso be employed to lock the device to the bone. The rings can be lockedto the fixation device in some embodiments. Additionally, the rings canbe threaded over the device. In other embodiments, a guide jig guidesscrews through the rings. Further self tapping screws lock the rings tothe bone and bone fixation device. A set screw can also be used to lockthe device at the fracture site. The device can also be stiffened. Inperforming the method of the invention, fracture fragments can bereduced.

The devices disclosed herein may be employed in various regions of thebody, including: cranial, thoracic, lower extremities and upperextremities. Additionally, the devices are suitable for a variety ofbreaks including, metaphyseal and diaphyseal.

The fracture fixation devices of various embodiments of the inventionare adapted to be inserted through an opening of a fractured bone, suchas the radius (e.g., through a bony protuberance on a distal or proximalend or through the midshaft) into the intramedullary canal of the bone.In some embodiments, the fixation device has two main components, oneconfigured component for being disposed on the side of the fractureclosest to the opening and one component configured for being disposedon the other side of the fracture from the opening so that the fixationdevice traverses the fracture.

The device components cooperate to align, fix and/or reduce the fractureso as to promote healing. The device may be removed from the bone afterinsertion (e.g., after the fracture has healed or for other reasons), orit may be left in the bone for an extended period of time orpermanently.

In some embodiments, the fracture fixation device has one or moreactuatable anchors or grippers on its proximal and/or distal ends. Theseanchors may be used to hold the fixation device to the bone while thebone heals.

In some embodiments, to aid in insertion into the intramedullary canal,at least one component of the fracture fixation device has asubstantially flexible state and a substantially rigid state. Once inplace, deployment of the device also causes the components to changefrom the flexible state to a rigid state to aid in proper fixation ofthe fracture. At least one of the components may be substantially rigidor semi-flexible. At least one component may provide a bone screwattachment site for the fixation device.

Embodiments of the invention also provide deployment tools with a toolguide for precise alignment of one or more bone screws with the fracturefixation device. These embodiments also provide bone screw orientationflexibility so that the clinician can select an orientation for the bonescrew(s) that will engage the fixation device as well as any desiredbone fragments or other bone or tissue locations.

The deployment tools also have features that help make it easier to use.For example, deployment tool components can be oriented so as to be usedby either the right hand or the left hand of the user. Also, certaindeployment tool components may be rotated out of the user's field ofvision during use without compromising the component's function.

These and other features and advantages of the present invention will beunderstood upon consideration of the following detailed description ofthe invention and the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

The novel features of the invention are set forth with particularity inthe appended claims. A better understanding of the features andadvantages of the present invention will be obtained by reference to thefollowing detailed description that sets forth illustrative embodiments,in which the principles of the invention are utilized, and theaccompanying drawings of which:

FIGS. 1A-E are views of an embodiment of a bone repair device accordingto the invention.

FIGS. 2A-D are views of flexible-to-rigid bodies.

FIGS. 3A-C are views of a scissor gripper component of the bone repairdevice of FIG. 1.

FIG. 4 is a cross-section of a ratchet, hub, gripper andflexible-to-rigid body components of the bone repair device of FIG. 1.

FIG. 5 is a retracted isometric view of the bone repair device of FIG.1.

FIGS. 6A-G are views of an alternative embodiment of a bone repairdevice according to the invention.

FIGS. 7A-B are views of a hub component of the bone repair device ofFIG. 6.

FIGS. 8A-B are views of a gripper component of the bone repair device ofFIG. 6.

FIG. 9 is a view of a ratchet component of the bone repair device ofFIG. 6.

FIG. 10A is a perspective view showing another embodiment of a bonerepair device in a retracted state.

FIG. 10B is a cross-sectional view taken along line 10 b-10 b in FIG. 10a.

FIG. 11A is a perspective view showing the bone repair device of FIGS.10 a and 10 b in a deployed state.

FIG. 11B is a cross-sectional view taken along line 11 b-11 b in FIG. 11a.

FIG. 12 is a cross sectional elevation view showing the bone repairdevice of FIG. 11 b.

FIGS. 13-18 show details of one embodiment of an actuatable gripper foruse with a fracture fixation device.

FIGS. 19-21 show yet another embodiment of a fracture fixation deviceaccording to the invention.

FIG. 22 shows a portion of fracture fixation device of FIGS. 19-21 in adeployed configuration.

FIGS. 23-25 show the fracture fixation device of FIGS. 19-22 deployedwithin a bone.

FIGS. 26-31 show details of a gripper for use with a fracture fixationdevice.

FIGS. 32 and 33 show yet another embodiment of a fracture fixationdevice according to the invention.

FIGS. 34-39 show a deployment tool for use with a fracture fixationdevice of this invention.

FIGS. 40-41 show another embodiment of a deployment tool for use with afracture fixation device of this invention

FIGS. 42-43 show the interaction between a flexible screw driver and theactuator of a fixation device.

FIGS. 44-48 show another embodiment of a gripper for use with a fracturefixation device.

FIGS. 49-50 show another embodiment of a fracture fixation devicesimilar to the device shown in FIGS. 19-25 using a distal grippersimilar to that shown in FIGS. 44-48 but using an alternativeactuator/locking mechanism.

FIGS. 51-52 show yet another embodiment of a fracture fixation devicesimilar to the device shown in FIGS. 49-50 but using another alternativeactuator and an alternative flexible-to-rigid body.

FIGS. 53-59 show alternative designs for the flexible-to-rigid body of afracture fixation device according to this invention.

FIGS. 60A-B show an alternative embodiment of a fracture fixation devicein a retracted state.

FIGS. 61A-B show the device of FIGS. 60 a-b in a deployed state.

FIGS. 62A-B show another embodiment of a gripper mechanism.

FIG. 63 shows an embodiment of an outrigger device.

DETAILED DESCRIPTION

By way of background and to provide context for the invention, it may beuseful to understand that bone is often described as a specializedconnective tissue that serves three major functions anatomically. First,bone provides a mechanical function by providing structure and muscularattachment for movement. Second, bone provides a metabolic function byproviding a reserve for calcium and phosphate. Finally, bone provides aprotective function by enclosing bone marrow and vital organs. Bones canbe categorized as long bones (e.g. radius, femur, tibia and humerus) andflat bones (e.g. skull, scapula and mandible). Each bone type has adifferent embryological template. Further each bone type containscortical and trabecular bone in varying proportions. The devices of thisinvention can be adapted for use in any of the bones of the body as willbe appreciated by those skilled in the art.

Cortical bone (compact) forms the shaft, or diaphysis, of long bones andthe outer shell of flat bones. The cortical bone provides the mainmechanical and protective function. The trabecular bone (cancellous) isfound at the end of the long bones, or the epiphysis, and inside thecortex of flat bones. The trabecular bone consists of a network ofinterconnecting trabecular plates and rods and is the major site of boneremodeling and resorption for mineral homeostasis. During development,the zone of growth between the epiphysis and diaphysis is themetaphysis. Finally, woven bone, which lacks the organized structure ofcortical or cancellous bone, is the first bone laid down during fracturerepair. Once a bone is fractured, the bone segments are positioned inproximity to each other in a manner that enables woven bone to be laiddown on the surface of the fracture. This description of anatomy andphysiology is provided in order to facilitate an understanding of theinvention. Persons of skill in the art will also appreciate that thescope and nature of the invention is not limited by the anatomydiscussion provided. Further, it will be appreciated there can bevariations in anatomical characteristics of an individual patient, as aresult of a variety of factors, which are not described herein. Further,it will be appreciated there can be variations in anatomicalcharacteristics between bones which are not described herein.

FIGS. 1 a-e are views of an embodiment of a bone repair device 100having a proximal end 10 (nearest the surgeon) and a distal end 20(further from surgeon) and positioned within the bone space of apatient) according to the invention. In the retracted side view shown inFIG. 1 a. the device sits along a longitudinal axis x. The devices 100can contain a plate, nail/plate combination, or a blade/platecombination and can be made from alloys, such as cobalt-chromiummolybdenum, stainless steel and titanium, or plastics such as UHMWPE,PEEK or PEKK. The proximal end and distal end, as used in this context,refers to the position of an end of the device relative to the remainderof the device or the opposing end as it appears in the drawing. Theproximal end can be used to refer to the end manipulated by the user orphysician. The proximal end may be configured such that a portionthereof remains outside the bone. Alternatively, the proximal end isconfigured such that it does not remain outside the bone. The distalend, thus, can be used to refer to the end of the device that isinserted and advanced within the bone and is furthest away from thephysician. As will be appreciated by those skilled in the art, the useof proximal and distal could change in another context, e.g. theanatomical context in which proximal and distal use the patient asreference.

When implanted within a patient, the device can be held in place withsuitable fasteners such as wire, screws, nails, bolts, nuts and washers.The device 100 is used for fixation of fractures of the proximal ordistal end of long bones such as intracapsular, intertrochanteric,intercervical, supracondular, or condular fractures of the femur; forfusion of a joint; or for surgical procedures that involve cutting abone. The devices 100 may be implanted or attached through the skin sothat a pulling force (traction may be applied to the skeletal system).

Turning now to FIG. 1 b. the design of this radius metaphyseal repairdevice depicted is adapted to provide a scissor-like engaging mechanismadapted to engage target bone of a patient from the inside of the bone.As configured for this anatomical application, the device is designed tofacilitate bone healing when placed in the intramedullary space within apost fractured bone. This device 100 had two sets of scissorgrippers—one positioned proximally near the hub 110 (shown scissored-outin FIG. 1 b and shown undeployed in FIG. 1 a) and one near the tip 110′.On entry into a cavity, both grippers 110, 110′ are flat and retracted(FIG. 1 a). Upon deployment, both grippers 110, 110′ scissor-out andgrip the diaphyseal bone from the inside of the bone. Screws (not shown)placed through apertures through the hub 120 lock the device 100 to themetaphyseal bone. Hence, the metaphysis and the diaphysis are joined. Aflexible-to-rigid body 130 is also provided positioned between the twogrippers 110, 110′. The embodiment of the flexible-to-rigid body 130 isconfigured to form dual helical springs whose inner and outer tubularcomponents coil in opposite directions. It is provided with spiral cuts132 for that purpose.

The bone fixation device 100 has an actuator 160 at a proximal end 10.The actuator 160 enables a user to control the movement, insertion,deployment, removal, and operation of the device. The actuator 160 has aratchet feature 444 as shown in FIG. 4. The anchoring segments 110 haveradially extending teeth or grippers that scissor out away from acentral axis x of the device and that are deployed upon actuation of thedevice 100. The grippers interlock the device with the bone.

A bearing segment 150 suitable for use in an actuable bone fixationdevice is provided at the distal end of the device. The bearing segmentcan be adapted to act as blunt obsturator adapted to facilitatepenetration of bone and to keep the tip of actuator 160 from digginginto bone during insertion. The bearing segment, as depicted, has asubstantially spherical dimension, with a lumen 152 positionedtherethrough. The lumen depicted in this embodiment has a constant, orsubstantially constant, diameter along its length suitable for receivingthe an actuator wire or guide wire 160 of a device 100. Actuator 160 isrigidly attached to bearing segment 150 and can be used separately fromdevice 100 to serve as a guide wire for reaming before device 100 isinserted into the bone. During insertion, device 100 is inserted intothe bone over the actuator 160 that also serves as a guide wire.Alternatively, Actuator 160 attached to bearing segment 150 can beassembled into device 100 and inserted as a unit into bone.

FIGS. 2 a-d are views of flexible-to-rigid bodies 230, 230′. Theflexible to rigid central body extends between the scissor grippersshown in FIG. 1. This feature is flexible upon entry into bone and rigidupon application of compressive axial force provided by tensioningactuator 160. Various embodiments exist only a few of which are depictedin FIG. 2. These include a dual helical spring 230 provided with spiralcuts 232 (FIG. 2 a), a chain of ball bearings with flats or roughenedsurfaces, a chain of cylinders with flats, features, cones, spherical orpointed interdigitating surfaces, wavy-helical cut tubes (FIGS. 2 c-d),two helical cut tubes in opposite directions (FIG. 2 b), springs, linearwires with interdigitating coils, and bellows-like structures.

The design of the flexible-to-rigid tubular body 230 allows asingle-piece design to maximize the transformation of the same body froma very flexible member that minimizes strength in bending to a rigidbody that maximizes strength in bending and torque when compressiveforces are applied in the axial direction at each end. The body 230 ismade, for example, by a near-helical cut on a tubular member at an angleof incidence to the axis somewhere between 0+ and 180″ from thelongitudinal axis x of the tubular body 230. The near-helical cut orwavy-helical cut is formed by the superposition of a helical curve addedto a cyclic curb that produces waves of frequencies equal or greaterthan zero per turn around the circumference and with cyclic amplitudegreater than zero. The waves of on segment nest with those above andbelow it, thus increasing the torque and bending strength and stiffnessof the tubular body when subjective to compressive forces. The taperedsurfaces formed by the incident angle allow each turn to overlap withthe segment above and below it, thus increasing the bending strengthwhen the body is in compression. Additionally, the cuts can be alteredin depth and distance between the cuts on the longitudinal x-axis alongthe length of the body 230 to variably alter the flexible-to-rigidcharacteristics of the tubular body along its length.

The cuts 232 in the body 230 allow an otherwise rigid member to increaseits flexibility to a large degree during deployment. The Tubular membercan have constant or varying internal and external diameters. Thisdesign reduces the number of parts of the flexible-rigid body of thedevice and allows insertion and extraction of the device through acurved entry port in the bone while maximizing its rigidity onceinserted. Application and removal of compressive forces provided by aparallel member such as wire(s), tension ribbons or a sheath willtransform the body from flexible to rigid and vice versa.

FIGS. 3 a-c are views of the scissor gripper 310 component of the bonerepair device 100 of FIG. 1. For purposes of illustration the distalgripper (110′ from FIG. 1 is depicted) with the obsturator 350. Thegrippers or clamp 310 are comprised of a four bar linkage 312 a, 312 b,312′, 312 a″, 312 b″, 312′″ analogous to an automotive scissor jack. Inthis embodiment the four bar linkage has free ends 313 beyond centralpivots 314, 314′ that translate radially, away from the longitudinalaxis x. These free ends interdigitate into bone and grip in bothdirections of axial force, elbow to wrist and wrist to elbow. Thetension force required by the grippers to attach to the bone decreasesas they expand away from the central axis x. The axial force (elbow towrist, wrist to elbow) to move the grippers increase as the grippersexpand away from the central axis. Any number of scissor gripperassemblies can be part of the overall device. The space between thegripper assemblies is occupied by the flexible to rigid central body asshown above. The scissor grippers are actuated by applying an axialforce F_(a) opposite the direction of entry of the device into bone. Forthe embodiment depicted in FIG. 3, a distal set of interior pivotingends 315, 315″ are adapted to pivotally engage the obsturator 350directly, or a connector 316′ adapted to engage the obsturator whichforms the distal end of the scissor gripper 310. A proximal set ofinterior pivoting ends 315′, 315′″ are adapted to engage a connector316. The connector 316 can be adapted to engage, for example, aflexible-to-rigid body. For a gripper adapted to be positionedproximally, e.g., near the ratchet, the distal set of interior pivotingends 315, 315″ would be adapted to pivotally engage a connector 316which is adapted to engage a flexible-to-rigid body. The proximal set ofinterior pivoting ends 315′, 315′″ would then be adapted to engage theratchet. Other configurations of the scissor gripper can be employed andadapted according to the placement of the scissor gripper along thelength of the device.

FIG. 4 is a cross-section of a ratchet component of the bone repairdevice of FIG. 1. A central ratcheting segment 440 of guide wire 460.This feature extends from the farthest surface of the device from thepoint of entry. It then extends back toward and completely through theresilient member 444 and metaphyseal hub 120. The central ratchetingguide wire has several functions. These include: guide wire for locationwithin bone; guide wire for telescoping reaming of the intramedullaryspace; guide wire for location of the scissor concept implant; fixativedatum for stopping intramedullary translation away from the point ofentry into bone; rigid actuation surface to provide compressive force tocollapse scissor grippers and make the flexible-to-rigid central bodyrigid; grooves 442, indentations, facets, changed surface features thatinteract with the resilient ratchet member 444 inside the metaphysealhub. These features allow single directional translation of the centralratcheting guide wire opposite to the direction of entry into bone, butprevent translation of the central ratcheting guide wire back into thebone; collapses the scissor grippers thereby causing interdigitationinto bone, this causes an expansion away from the central axis; allowsthe surgeon to cut off the central ratcheting guide wire so that it isbelow the outer surface of the metaphyseal hub and below the bonesurface at the point of entry. For removal, once the resilient ratchetmember is deflected away from the grooves, indentations, facets, changedsurface features, the central ratcheting guide wire can be pushed awayfrom the point of entry into bone, thereby collapsing the scissorgrippers towards the central axis of the scissor concept implant;through out all of the functions of the central ratcheting guide wire,it is flexible and allows the scissor concept implant to bend around aradius of curvature less than 1.6 inches. The ratchet controls thelocking and unlocking of the axial motion of the device.

FIG. 5 is a refracted isometric view of the bone repair device 500 ofFIG. 1.

FIGS. 6 a-g are views of an alternative embodiment of a bone repairdevice according to the invention. Similar to the device depicted inFIG. 1, the device 600 can also be constructed from component parts. Afeature of the device 600 is that its design it enables transmission offixation forces to healthy unbroken bone. Another feature of the device600 enables the device 600 to achieve asymmetric flexibility by usingparts that increase a moment of inertia in a single axis. The moment ofinertia of a point mass with respect to an axis is the product of themass times the distance from the axis squared. The moment of inertia ofany extended object, which applies in this instance, is a variant fromthat basic definition. The moment of inertia is important in anembodiment of a bone fixation, repair, or reinforcement device sinceflexibility in one plane and rigidity in a plane coincident and normalto said plane is required. This is achieved through the selective usedof materials and specific geometric definition.

The design of the radius metaphyseal repair assembly device 600 depictedherein facilitates bone healing when placed in the intramedullary spacewithin a post-fractured bone. This device 600 had two sets ofdiaphyseal-facing grippers 610 and two sets of metaphyseal-facinggrippers 610′. All grippers 610, 610′ are retracted during insertion.Upon deployment, all 4 prongs 612 on each of the 4 gripper sets pushinto the diaphyseal bone—preventing motion in either direction. Screws(not shown) can be placed through the hub 620 (on the right side) tolock the device position with respect to the metaphyseal bone. Hence,the metaphysis and the diaphysis are joined.

This device 600 had two sets of distal grippers—one positionedproximally near the distal tip 610 (shown scissored-out in FIGS. 6 a-b);additionally a set of proximal grippers 611 can be provided. Asdepicted, the proximal grippers 611 deploy at a perpendicular angle tothe deployment angle of the distal grippers. On entry into a cavity, thegrippers 610 are flat and unfolded. Upon deployment, the grippers 610extent away from the central axis X and grip the diaphyseal bone. Screws(now shown) placed through apertures (not shown) in the hub 620 lock thedevice 600 to the metaphyseal bone. Hence, the metaphysis and thediaphysis are joined. A central body 630 is also provided positionedbetween the grippers 610. The central body 630 as depicted is configuredto surround at least a portion of the guide wire 660.

The bone fixation device 600 has an actuator 660 at a proximal end 10.The actuator 660 enables a user to control the movement, insertion,deployment, removal, and operation of the device. The actuator 660traverses ratchet feature 640 as shown in FIG. 9. The anchoring segments610 have radially extending teeth or grippers that extend away from acentral axis X of the device 600 and that are deployed upon actuation ofthe device 600. The grippers 610 interlock the device 600 with the bone.Ratchet feature 640 allows the actuator 660 to translate axially in thedirection of deployment and keeps actuator 660 under tension.

A bearing segment 650 suitable for use in an actuable bone fixationdevice is provided at the distal end of the device. The bearing segmentcan be adapted to act as blunt obsturator adapted to facilitatepenetration of bone. The bearing segment, as depicted, has asubstantially spherical dimension, with a lumen 652 positionedtherethrough. The lumen depicted in this embodiment has a constant, orsubstantially constant, diameter along its length suitable for receivingthe drive shaft or guide wire 660 of a device 600. Guide wire 660 alsoserves as actuator 660.

As shown in FIG. 6 e, the grippers 610, 610′ are configured to engage abead 614 with apertures 615 through which the lateral lengths of thegrippers fit. A low profile tube 616 is also provided which is adaptedto fit within a central aperture of the beads 614. Tendons 618 are alsoprovided. The tendons serve a variety of functions as would beappreciated by those skilled in the art. In one instance, the tendonsprovide for greater effective moment of inertia in the Z-direction,which is the plane normal to the dorsal plane or the volar surfaces ofthe wrist. The tendons 618 also actuate the grippers in and out of thesheath. Pulling the tendons 618 makes the grippers of the device extendout of the device sleeve, thus penetrating bone. Once the gripperspenetrate bone, the device is anchored.

FIGS. 7 a-b are views of a hub 720 component of the bone repair deviceof FIG. 6. The metaphysial hub is adapted to engage the repair device600 at its distal end 20 and is adapted to engage a lock 680 at isproximal end 10. The metaphyseal hub is a component of the device thatperforms several functions:

Structural Linkage Between Different Compositions of Bone

First, the metaphyseal hub 720 creates the structural linkage betweenthe transitional sections of bone. These are the exterior cortex ofbone, the metaphysis, and the diaphysis. The hub can be rigid orflexible. In these embodiments the metaphyseal hub is made of a rigidthermoplastic polymer. Examples of these materials includepolyetheretherketone, polyaramids, such as nylon, and ultra highmolecular weight polyethylene. The primary advantages of theseengineering thermoplastic polymers include geometric conformity to thetransition of bone, geometric conformity to the transitional geometry ofthe device from the exterior cortex through the metaphysis and thediaphysis. In these embodiments the shape of the metaphyseal hub had acircular, tubular shape, curved at a constant radius.

Curved to Allow Minimally Invasive Access to the Intramedullary Space

In some embodiments of the invention, the radius of curvature for thehub 720 is between 2.0 inches to 0.5 inches. The radius of curvatureallowed for the angle of penetration through the exterior cortex of thebone to be between 80 degrees from perpendicular to perpendicular to thebone. In the case of the radius the “bone” as described, would be theradial styloid. The circular cross section is designed to match accesshole.

The diameter of the cross sectional circular area of the tubularmetaphyseal hub 720 is between 0.020 inches to 2 inches as determined bythe size of the intramedullary space of the bone that is under repair.The circular cross-section helps to minimize trauma.

Interface to Metaphyseal Bone Attachment Devices (Screws)

The metaphyseal hub 720 allows the placement of bone screws (not shown)or other devices that secure the metaphyseal bone to the metaphysealhub. In the case of screws, a thermoplastic metaphyseal hub allows thesurgeon to drill pilot holes from bone, through the metaphyseal hub, andinto bone. A screw that is larger in diameter than the pilot hole wouldbe inserted with a twisting motion and interfere with bone, themetaphyseal hub, and bone. This construction allow secure fixation ofthe distal fragments (proximal to the surgeon) of the fractured bone todevice 600 which in turn is secured to the proximal side of thefractured bone. (distal to the surgeon)

Interface to the Drilling and Screw Placement Outrigger

The metaphyseal hub 720 can also be adapted to interface with anoutrigger (See, co-pending application Ser. No. 60/866,976 filed Nov.22, 2006 to Phillip Jobson for SURGICAL TOOLS FOR USE IN DEPLOYING BONEREPAIR DEVICES which describes an outrigger tool). The outrigger allowsexact placement of bone screws so that the screws penetrate bone, thenthe metaphyseal hub, then the bone on the opposite side of themetaphyseal hub. This hub interface can be a thread, bayonet stylespring loaded contact, snap fit, interference fit, or other alternatelyfixative and stable attachment with removability

Interface to the Diaphyseal Fixation Section

The metaphyseal hub 720 has an interface to the diaphyseal fixationsection of the device 600. This interface attaches the diaphysealfixation section to the metaphyseal section provides an alternately,reversible, actuator or ratchet 640. This actuator 640 allows singledirection translation of the actuator rod 660 or ratcheting guide wirethat deploys the diaphyseal cortical interfacial attachment moieties.

FIGS. 8 a-b are views of a gripper 810 component of the bone repairdevice of FIG. 6. The gripper 810 is configured to form a flat bottomedu-shape (similar to a staple). The two sides 811, 811′ are configured toflare away from a central axis x of the gripper during deployment. Theends of the grippers can be shaped such that they are sharply pointed812.

FIG. 9 is a view of a ratchet component of the bone repair device ofFIG. 6. A central ratcheting element 944 is traversed by guide wire 960with grooves 942. This feature extends from the farthest surface of thedevice from the point of entry. It then extends back toward andcompletely through the resilient member and metaphyseal hub. The centralratcheting guide wire has several functions. These include: guide wirefor location within bone; guide wire for telescoping reaming of theintramedullary space; guide wire for location of the scissor conceptimplant; fixative datum for stopping intramedullary translation awayfrom the point of entry into bone; rigid actuation surface to collapsescissor grippers and make the flexible to rigid central body rigid;grooves 942, indentations, facets, changed surface features thatinteract with the resilient ratchet member 944 inside the metaphysealhub. These feature allow single directional translation of the centralratcheting guide wire 960 towards the point of entry into bone, butprevent translation of the central ratcheting guide wire away point ofentry into bone; collapses the scissor grippers thereby causinginterdigitation into bone, this causes an expansion of the grippers awayfrom the central axis; allows the surgeon to cut off the centralratcheting guide wire so that it is below the outer surface of themetaphyseal hub; once the resilient ratchet member is deflected awayfrom the grooves, indentations, facets, changed surface features, thecentral ratcheting guide wire can be pushed away from the point of entryinto bone, thereby collapsing the scissor grippers towards the centralaxis; through out all of the functions of the central ratcheting guidewire, it is flexible and allows the bone fixation devices such as device600 to bend around a radius of curvature less than 1.6 inches. Theratchet locks and releases the axial and angular position of the device.

A corollary embodiment of the previously described art include axialtranslation from distal to proximal ends of the device thereby drawingbone and tissue together through shortening the axial distance distal toproximal between the two sides of the fracture(s). These embodimentshave specific applications in fracture non-unions, joint fusions andcertain fractures that require the compression of the fracture surfaces.

Additional embodiments, methods, and uses are envisioned in accordancewith the inventive attributes. One embodiment of the present inventionprovides a low weight to volume mechanical support for fixation,reinforcement and reconstruction of bone or other regions of themusculo-skeletal system. The method of delivery of the device is anotheraspect of the invention. The method of delivery of the device inaccordance with the various embodiments of the invention reduces thetrauma created during surgery, decreasing the risks associated withinfection and thereby decreasing the recuperation time of the patient.The framework may in one embodiment include an expandable andcontractible structure to permit re-placement and removal of thereinforcement structure or framework.

In accordance with the various embodiments of the present invention, themechanical supporting framework or device may be made from a variety ofmaterials such as metal, composite, plastic or amorphous materials,which include, but are not limited to, steel, stainless steel, cobaltchromium plated steel, titanium, nickel titanium alloy (nitinol),superelastic alloy, and polymethylmethacrylate (PMMA). The supportingframework or device may also include other polymeric materials that arebiocompatible and provide mechanical strength, that include polymericmaterial with ability to carry and delivery therapeutic agents, thatinclude bioabsorbable properties, as well as composite materials andcomposite materials of titanium and polyetheretherketone (PEEK™),composite materials of polymers and minerals, composite materials ofpolymers and glass fibers, composite materials of metal, polymer, andminerals.

Within the scope of the present invention, each of the aforementionedtypes of device may further be coated with proteins from synthetic oranimal source, or include collagen coated structures, and radioactive orbrachytherapy materials. Furthermore, the construction of the supportingframework or device may include radio-opaque markers or components thatassist in their location during and after placement in the bone or otherregion of the musculo-skeletal systems.

Further, the reinforcement device may, in one embodiment, be osteoincorporating, such that the reinforcement device may be integrated intothe bone.

In a further embodiment, there is provided a low weight to volumemechanical supporting framework or device deployed in conjunction withother suitable materials to form a composite structure in-situ. Examplesof such suitable materials may include, but are not limited to, bonecement, high density polyethylene, Kapton®, polyetheretherketone(PEEK™), and other engineering polymers.

Once deployed, the supporting framework or device may be electrically,thermally, or mechanically passive oractive at the deployed site withinthe body. Thus, for example, where the supporting framework or deviceincludes nitinol, the shape of the device may be dynamically modifiedusing thermal, electrical or mechanical manipulation. For example, thenitinol device or supporting framework may be expanded or contractedonce deployed, to move the bone or other region of the musculo-skeletalsystem or area of the anatomy by using one or more of thermal,electrical or mechanical approaches.

The invention also includes a method for repairing a bone fracturecomprising: accessing a fracture along a length of bone through a bonyprotuberance at an entry portal; introducing the bone fixation deviceinto the medullary canal through the entry portal; bending the bonefixation device along its length to advance into the medullary space inthe bone; bending the bone fixation device along its length to traversethe fracture site; placing a flexible elbow in the medullary canal atthe fracture site; stiffening the bone fixation device; locking the bonefixation device to the bone; reducing the fracture with the bonefixation device in place in the medullary canal; locking the flexibleelbow to achieve intramedullary reduction of the fracture. The methodcan further include the step of introducing a guide wire into themedullary space through a bony protuberance at an entry portal.Additionally, the guide wire can be reamed through the bony protuberanceat an entry portal. The location of the reamed boney canal can bedetermined by the fracture geometry and bone anatomy. In someembodiments of the method, a sleeve can be advanced along the bonefixation device. In such embodiments, the sleeve can function to unlockthe spikes from the fixation device. Once the spikes are unlocked fromthe fixation device, the spikes then fix the device to the bone. Lockingbutterfly rings can also be employed to lock the device to the bone. Thebutterfly rings can be locked to the fixation device in someembodiments. Additionally, the rings can be threaded over the device. Inother embodiments, a guide jig guides screws through the butterflyrings. Further self tapping screws lock the butterfly rings to the boneand bone fixation device. A set screw can also be used to lock thedevice at the fracture site. The device can also be stiffened. Inperforming the method of the invention, fracture fragments can bereduced.

Yet another aspect of the invention includes a barb-screw comprising asleeve, one or more teeth deployable at a distal end of the sleeve, andan actuable lock adapted to secure the sleeve within the space of thebone from an end of the device.

Where the proximal end of a device in the anatomical context is the endclosest to the body midline and the distal end in the anatomical contextis the end further from the body midline, for example, on the humerus,at the head of the humerus (located proximal, or nearest the midline ofthe body) or at the lateral or medial epicondyle (located distal, orfurthest away from the midline); on the radius, at the head of theradius (proximal) or the radial styloid process (distal); on the ulna,at the head of the ulna (proximal) or the ulnar styloid process(distal); for the femur, at the greater trochanter (proximal) or thelateral epicondyle or medial epicondyle (distal); for the tibia, at themedial condyle (proximal) or the medial malleolus (distal); for thefibula, at the neck of the fibula (proximal) or the lateral malleoulus(distal); the ribs; the clavicle; the phalanges; the bones of themetacarpus; the bones of the carpus; the bones of the metatarsus; thebones of the tarsus; the sternum and other bones, the device will beadapted and configured with adequate internal dimension to accommodatemechanical fixation of the target bone and to fit within the anatomicalconstraints. As will be appreciated by those skilled in the art, accesslocations other than the ones described herein may also be suitabledepending upon the location and nature of the fracture and the repair tobe achieved. Additionally, the devices taught herein are not limited touse on the long bones listed above, but can also be used in other areasof the body as well, without departing from the scope of the invention.It is within the scope of the invention to adapt the device for use inflat bones as well as long bones.

The devices disclosed herein can be deployed in a variety of suitableways, as would be appreciated by those skilled in the art. For example,a provisional closed reduction of the fracture can be performed whereina 1.5 to 2 inch incision is made overlying the metaphyseal prominence ofthe bone. Blunt dissection is then carried to the fascia whereupon thefascia is incised. The surgical approach to the central aspect(anterior-posterior) proceeds by either splitting the tendon or ligamentor muscle longitudinally or by elevating structures of the bone in asubperiosteal fashion. The choice of the particular approach varies withrespect to the fractured bone that is being treated. A specialized softtissue retractor is placed onto the bone retracting the soft tissuesaway from the entry point of the bone.

A guide wire can then be drilled at an angle into the insertion pointalong the metaphyseal prominence. The angle of placement of the guidewire along the longitudinal axis of the bone depends on the fractureanatomy and particular bone being treated. The guide wire can then beplaced under fluoroscopic guidance. An optimally chosen reamer isintroduced over the guide wire opening the metaphyseal entry point. Bothdevices are then removed.

A curved guide wire is introduced across the open channel of themetaphysis and is advanced across the fracture site into the diaphysisof the bone. Sequential reaming appropriate for the particular device isperformed to prepare the diaphysis. The distance from the fracture siteto the entry point is estimated under fluoroscopy and the appropriatedevice is selected. The reamer is withdrawn and the device is introducedover the guide wire into the metaphysis and across the fracture into thediaphysis. Fluoroscopy confirms the location of the universal joint atthe metaphyseal/diaphyseal fracture site. Alternatively, the device isintroduced into the metaphysic after the removal of the guide wire.

The diaphyseal teeth of the device are deployed and the device isrigidly fixed to the diaphysis of the fractured bone distal to thefracture site. Any extension of the fracture into the joint can now bereduced in a closed fashion and held with K wires or in an open fashionvia a dorsal approach to the intra-articular portion of the fracture.Metaphyseal locking flanges with targeting outriggers attached are nowadvanced (in to the metaphyseal bone) across the metaphysis. Using theattached targeting outrigger, guide wires are now placed through themetaphyseal locking flanges. The guide wires are directedfluoroscopically to stabilize the intra-articular portion of thefracture and/or to stabilize the metaphyseal fracture securely. Holesare drilled over the guide wires with a cannulated drill bit, oralternatively, holes are drilled guided by the outrigger without the useof guidewires and with a non-canulated drill bit. Then, self tappingscrews are advanced over the guide wires to lock the bone to the shaftand metaphyseal locking flange or alternatively, self tapping screws areadvanced guided by the outrigger without the use of a guide wire to lockthe bone to the shaft and metaphyseal locking flange. The device is nowlocked within the proximal and distal bone fragments (metaphyseal ordiaphyseal) and distal (diaphyseal) bone. This provides for rigidfixation of the comminuted intra-articular fragments to each other, andthe fixation between these screws interlocking in to the metaphysealflange component provides rigid fixation of these intra-articularfragments in the metaphyseal region to the diaphyseal shaft as well. Theextremity and fracture is now manipulated until a satisfactory reductionis achieved as visualized under fluoroscopy. Thereafter, the fracture ismanipulated under fluoroscopic guidance in order to achieve anatomicalignment of the bone fragments. Once optimal intramedullary reductionis achieved, the universal joint is locked. The fracture is now fixedsecurely. The guide wire is removed and the wound is closed repairingthe periosteum over the metaphyseal entry point and repairing the fasciaand closing the skin. A splint may be applied.

The embodiments shown in FIGS. 10 a-b, 11 a-b and 12 are describedbelow, after the discussion of FIGS. 13-59.

FIGS. 13-15 show details of an actuatable gripper 1070 for use with,e.g., the fracture fixation device embodiments described above. In thisembodiment, gripper 1070 has two rotatable cams 1072 and 1074. Cams 1072and 1074 are attached by pins 1073 and 1075 to cam arms 1076 and 1078,respectively. Pins 1073 and 1075 are rotationally and axially fixed tocams 1072 and 1074. Pins 1073 and 1075 are axially fixed to arms 1076and 1078 but free to move rotationally. Arms 1076 and 1078 are attachedby pins 1077 and 1079 to flanges 1080 and 1082, respectively. Pins 1077and 1079 are axially and rotationally fixed to flanges 1080 and 1082,but arms 1076 and 1078 are only constrained axially and free to moverotationally. Flanges 1080 and 1082 connect with the components oneither end of the device. In the undeployed configuration shown in FIGS.13 and 14, cams 1072 and 1074 are oriented such that the sharp tips 1085and 1087 of cam 1072 and the sharp tips 1081 and 1083 of cam 1074 do notextend from the cylinder of the gripper. When foreshortened duringdeployment, however, movement of flanges 1080 and 1082 toward each othercauses cam arms 1076 and 1078 to rotate about pins 1077 and 1079 withrespect to flanges 1080 and 1082 and causes cams 1072 and 1074 to rotateabout pins 1073 and 1075 with respect to cam arms 1076 and 1078 so thatthe sharp tips swing out from the cylinder of the gripper, as shown inFIG. 15. Thus, when part of a fracture fixation device that has beeninserted into a bone, deployment of the gripper 1070 causes the sharptips of the cams to dig into the bone to anchor the device. Analternative design combines cams 1072 and 1074 into one integralcomponent.

In order to prevent inadvertent deployment of the gripper, one or moreoptional lock wires may be inserted into the gripper. As shown in FIG.13, lock wire channels 1084 and 1086 may be formed in flanges 1080 and1082, and corresponding channels may be formed in flange 1080. Likewise,lock wire channels may be formed in the cams, such as channel 1088formed in cam 1074, to line up with the lock wire channels formed in theflanges when the gripper is in its undeployed configuration, therebypermitting a lock wire 1089 to be inserted through the gripper, as shownin FIG. 14. Lock wire 1089 must be removed before the gripper can berotated to its foreshortened deployed configuration, as shown in FIG.15. A lock wire may also be inserted across the gripper through holes1071.

FIGS. 16-18 show a gripper 1090 for use on one end of an actuatablefracture fixation device according to one embodiment of the invention.In this embodiment, a threaded flange 1092 replaces flange 1082 of theearlier gripper embodiment. Internal threads 1094 in flange 1092interact with a threaded actuator, such as actuator 1614 shown in FIGS.10 and 11, for use in foreshortening during deployment.

FIG. 18 also demonstrates an advantage of the grippers 1070 and 1090shown in FIGS. 13-18. During insertion into the interior of a bone alonga curved insertion path, grippers 1070 and 1090 can adapt to the curveof the insertion path, as shown by the curved line in FIG. 18.

FIGS. 19-21 show yet another embodiment of a fracture fixation device1100 according to the invention. In this embodiment, device 1100 has afirst gripper 1102 constructed, e.g., like the grippers described abovewith respect to FIGS. 13-18, and a second gripper 1104. Extendingbetween grippers 1102 and 1104 is a flexible-to-rigid body 1106. Athreaded actuator 1108 with a blunt end 1110 extends through grippers1102 and 1104, body 1106 and an internally threaded head 1112. A toolengagement feature 1114 extends from one end of actuator 1108 to enablea screw driver or other tool to rotate actuator 1108 to actuate,foreshorten and rigidize fracture fixation device 1100. A curved hub1116 is attached to the device distal to gripper 1104 (distal relativeto the patient). Pins 1111 secure hub 1116 and actuator 1108 axially tothe device while still permitting the actuator to rotate with respect tothe device and hub. A flange 1113 formed in tool engagement feature 1114engages a lip 1109 formed on the inside of hub 1116 to transfer anyloads from the actuator directly to the hub to avoid overloading pins1111. Internal threads 1118 in hub 1116 provide for attachment to adeployment tool (such as, e.g., tool 1300 shown in FIGS. 34-41) or forthe insertion of a plug (not shown) after deployment of fracturefixation device 1100 within a fractured bone. Hub 1116 that transversesthe fracture is designed with a larger external diameter than the restof the device. This features in the hub 1116 limits, during the healingprocess of the fracture, the amount of bone in-growth and calluses thatwould otherwise prevent the removal of the device. The external diameterof the hub 1116 is preferably also tapered to facilitate the release andremoval of the device. The larger diameter of the hub 1116 duringwithdrawal leaves behind an opening larger than the rest of the devicesuch as the grippers 1104, 1108 and flex-to-rigid body 1106 and thusfacilitates the removal of the device.

FIG. 22 shows device 1100 of FIGS. 19-21 without hub 1116, actuator 1108and blunt end 110. As shown, grippers 1102 and 1104 are in the deployedconfiguration.

FIGS. 23-25 show fracture fixation device 1100 of FIGS. 19-22 deployedwithin a space 1118 formed in a bone 1120. Device 1100 has been insertedthrough an opening 1122 formed in a bony protuberance of bone 1120, andthe grippers 1102 and 1104 have been actuated to grip the interior ofthe bone. Appropriate tools (such as those discussed herein) have beenused to form space 1118 with a curved distal portion (distal withrespect to the patient) extending proximally from opening 1122 to asubstantially straight proximal portion through one or more fractureareas, such as fracture lines 1124 and 1126. As shown, hub 1116 isdisposed within the curved portion of space 1118 while flexible-to-rigidbody 1106 and the grippers 1102 and 1104 are disposed in thesubstantially straight portion of space 1118. During delivery to space1118 in the device's undeployed configuration, grippers 1102 and 1104and body 1106 are substantially flexible so as to accommodate the curveof the distal portion of the opening. After actuation, however, thedevice body 1106 becomes rigid through the compression and interactionof its segments during foreshortening and deployment of grippers 1102and 1104.

In this embodiment, hub 1116 is substantially rigid and has a curveapproximating that of the curved portion of opening 1118. In someembodiments of the method of this invention, some or all of hub 1116 isplaced on one side of a bone fracture while the remainder of thefracture fixation device is placed on the other side of the fracture.

In some embodiments, hub 1116 is made of PEKK or PEEK implantable gradematerial and may be injection molded. Using the tools of this invention,a hole through bone 1120 may be drilled at any angle and through anyportion of hub to permit a screw to be inserted through the bone andfixation device. In FIG. 23, one screw 1128 has been inserted throughhub 1116 to help anchor device 1100 within the bone and to hold bonefragment 1125 to the main portion of the bone 1120. In FIGS. 24 and 25,multiple screws 1128 have been inserted in various positions andorientations. These figures illustrate the ability to place screwswherever needed and at whatever orientation required.

According to aspects of the invention, it has been discovered thatplacing a screw 1128 through the back of hub 1116 and just below thesubchondral bone (superficially and proximally of the subchondral bone)prevents the subchondral bone from moving proximally after removal ofthe cast. This undesirable subchondral bone migration can otherwiseoccur when forces from the hand tendons crossing the fracture draws thesubchondral bone proximately (relative to the patient) when the hand isused before the bone fracture is completely healed. In some embodimentsof the invention, it is preferable to insert at least one screw 1128 ina dorsal to volar direction, and at least one other screw in a volar todorsal direction, such as shown by the example depicted in FIG. 24. Suchan arrangement of screws 1128 may form a cross pattern as shown, orscrews 1128 may be generally parallel but in opposing directions. Insome embodiments, it is desirable to form a cross pattern so as tocapture four cortices of bone around the fracture. A third screw can beadded in a more proximal to distal orientation to form a very strongtriangle of bone fixation. Screw holes in hub 1116 may be preformed, maybe formed in situ, or a combination thereof.

FIGS. 26-31 show details of a gripper 1104 for use with a fracturefixation device, such as the devices of FIG. 1-5, 6-12 or 19-25. FIGS.26 and 27 show gripper 1104 in an undeployed configuration. FIGS. 28-31show gripper 1104 in deployed configurations. Gripper 1104 has threesets of anchor elements, with each set including a first anchor leg 1130and a second anchor leg 1132. Anchor leg 1130 is connected to flange1134 and extends toward flange 1136, and anchor leg 1132 is connected toflange 1136 and extends toward flange 1134. Legs 1130 and 1132 arerotatably connected by a pin 1138 that is fixedly attached to leg 1130.Leg 1132 rotates freely about pin 1138. A larger head portion 1139 onpin 1138 keeps leg 1132 rotatably mounted on pin 1138. In the undeployedconfiguration of FIGS. 26 and 27, legs 1130 and 1132 lie substantiallyparallel to each other within the circular projection of flanges 134 and136. When the fracture fixation device is actuated by, e.g., turning anactuator 1108 to foreshorten the device (as shown in FIG. 31), flanges1134 and 1136 are moved closed together. This movement causes the outeredges 1140 and 1142 of legs 1130 and 1132, respectively, to rotateradially outwardly to grip the inside surface of the bone in a deployedconfiguration, as shown, e.g., in FIGS. 23-25. Movement of flanges 1134and 1136 away from each other retracts legs 1130 and 1132 toward andinto their undeployed configuration for repositioning and/or removal ofthe device from the bone. Cut-outs 1135 formed in gripper 1104 mate withcorresponding shapes in the hub to provide a rotational keying featureenabling the transmission of torque from the hub to the rest of thedevice without overloading the pins connecting the hub to gripper 1104,as shown in FIGS. 29 and 31.

FIGS. 32 and 33 show yet another embodiment of a fracture fixationdevice according to the invention. Like the embodiment shown in FIGS.19-31, device 1200 has a curved hub 1216, a distal gripper 1204 (formed,e.g., like gripper 104 of the prior embodiment), a flexible-to-rigidbody 1206 and two proximal grippers 1201 and 1202 (each formed, e.g.,like gripper 102 of the prior embodiment). Pins 1211 attach hub 1216 togripper 1204. As in the embodiment of FIGS. 19-31, a threaded actuator1208 cooperates with an internally threaded head 1212 to foreshorten andactuate the device. The sectional view of FIG. 33 shows a threaded plug1217 that has been inserted into the distal opening of hub 1216 to sealthe device after actuation.

As seen from the discussion above, the devices of this invention can beeasily modified by adding grippers or by placing grippers in differentpositions on the device to address fractures where more gripping forcesare needed.

FIGS. 34-39 show a deployment tool 1300 for use with a fracture fixationdevice 100 of this invention. As shown in FIG. 34, the hub 1116 offixation device 1100 connects to a stem 1302 of tool 1300. Hub 1116 maybe provided with, e.g., alignment features 1115 and attachment features1114 for this purpose, as shown, e.g., in FIG. 23. This connectionorients fixation device 1100 with tool 1300. In particular, tool 1300aids in the use of a fixation device actuation tool and alignment of adrill with the fixation device's hub after the device has been deployedwithin a fractured bone and in the insertion of screws into the hub andbone.

Access to the interior of fixation device 1100 is provided by a port1304 through stem 1302 so that, e.g., a flexible screw driver 1306 maybe inserted through hub 1116 to device feature 1114 of actuator 1108, asshown in FIG. 36. Rotation of flexible screw driver 1306 and actuator1108 moves device 1100 from an undeployed flexible configuration to adeployed rigid configuration, as shown in FIGS. 42 and 43 (which showthe interaction of flexible screw driver 1306 and fixation device 1100outside of tool 1300). A flexible ring 1308 may be provided to interactwith a groove 1310 formed in flexible screw driver 1306 to provideproper axial positioning between the screw driver and the toolengagement feature 1114 of actuator 1108 while still permitting theflexible screw driver to rotate.

Tool 1300 also helps orient a drill and enables it to find the hub ofthe fixation device even when the fixation device is inside the bone andcannot be seen by a user. When fixation device 1100 is properly attachedto stem 1302, the bore 1321 of drill guide 1320 points toward thedevice's hub 1116 even when the drill guide is rotated along curvedguide 1300 or translated along grooves 326. In order to provide the userwith flexibility in drill placement (e.g., in order to place one or morescrews through hub 1116 as shown in FIGS. 23-25), tool 1300 permitsdrill guide 1320 to be moved with respect to stem 1302 and attached hub1116. Drill guide 1320 may be translated proximally and distally withrespect to hub 1116 by loosening knob 1322 and moving support 1324 alonggrooves 1326. In addition, drill guide 1320 may be rotated about hub1116 by loosening knob 1328 and moving drill guide 1320 along curvedgroove 1330.

FIGS. 37-41 show tool 1300 being used to guide a drill 1332 toward andthrough hub 116 (and through the bone, as shown in FIG. 41). The drillsleeve 1333 surrounding drill bit 1332 is held in place within bore 1321by a thumb screw 1334. An external x-ray visible aim 1340 may extendfrom drill guide 1320 to show on x-rays the orientation of the drill bit1332 and projected trajectory within the patient's bone, as shown inFIG. 39. The drill bit may be provided with a scale to show depth of thedrilled hole and, therefore, the length of the screw needed. In someembodiments, the drill 332 may have a sharp tip to reduce skittering ofthe drill against the device hub and/or bone during drilling. The tipincluded angle may be less than 100.0 degree. and preferably between25.0 degree. and 35.0 degree. to ensure penetration of the hub.

FIGS. 40-41 show an alternative planar tool 11300 being used to guide adrill 11332 toward and through the hub 1116 of a fracture fixationdevice. As with the earlier embodiment, access to the interior offixation device 1100 is provided by a port 11304 through a stem 11302 sothat, e.g., a flexible screw driver may be inserted through hub 1116 todevice actuator 1108. A flexible ring 11308 may be provided to interactwith a groove formed in the flexible screw driver to provide properaxial positioning between the screw driver and the tool engagementfeature 1114 of actuator 1108 while still permitting the flexible screwdriver to rotate.

Like the deployment tool described above, tool 11300 also helps orient adrill and enables it to find the hub of the fixation device even whenthe fixation device is inside the bone and cannot be seen by a user.When fixation device 1100 is properly attached to stem 11302, the boreof drill guide 11320 points toward the device's hub 1116 even when thedrill guide is translated along grooves 11326 or is rotated above theaxis of knob 11322. In order to provide the user with flexibility indrill placement (e.g., in order to place one or more screws through hub1116 as shown in FIGS. 23-25), tool 11300 permits drill guide 11320 tobe moved with respect to stem 11302 and attached hub 1116. Drill guide11320 may be translated proximally and distally with respect to hub 1116by loosening knob 11322 and moving support drill guide 11320 alonggrooves 11326. In addition, drill guide 11320 may be rotated about stem11302 and hub 1116.

FIGS. 44-48 show another embodiment of a gripper 1350 for use with afracture fixation device. As shown, gripper 1350 is designed to be usedon the leading end of the fixation device. It should be understood thatthis gripper could be used at other points in the fixation device aswell.

Extending between flange 1352 and nose cone flange 1354 are two sets ofanchor elements. Anchor legs 1356 are rotatably attached to flange 1352and extend toward flange 1354, and split anchor legs 1358 are rotatablyattached to nose cone flange 1354 and extend toward flange 1352. Anchorlegs 1356 are disposed in the split 1357 of anchor legs 1358. Legs 1356and 1358 are rotatably connected by a pin 1360. In the undeployedconfiguration of FIGS. 44 and 45, legs 1356 and 1358 lie substantiallyparallel to each other within the cylinder of flanges 1352 and 1354.When the fracture fixation device is actuated by, e.g., turning anactuator to foreshorten the device, flanges 1352 and 1354 are movedcloser together. This movement causes the outer edges 1362 and 1364 oflegs 1356 and 1358, respectively, to rotate outward to grip the insidesurface of the bone in a deployed configuration, as shown, e.g., inFIGS. 46-48. Movement of flanges 1352 and 1354 away from each otherretracts legs 1356 and 1358 toward and into their undeployedconfiguration for repositioning and/or removal of the device from thebone. A lock wire (shown in phantom in FIG. 44) disposed in channels1366 formed in projections 1368 extending between the two sides of theproximal anchor legs 1358 prevents inadvertent actuation of the anchors.Stop surfaces 1370 and 1372 on flanges 1352 and 1354, respectively, meetto provide a limit to extension of gripper 1350, as shown in FIG. 48.

FIGS. 49-50 show another embodiment of a fracture fixation device 1400similar to device 1100 shown in FIGS. 19-25 using a distal gripper 1402similar to that shown in FIGS. 44-48. Instead of a threaded rotatingactuator, however, device 1400 uses a ratcheting actuator 408. Actuatorpasses through device hub 1416, gripper 1402 and flexible-to-rigid body1406 to a flange (not shown) at the other end of the fixation device. Toforeshorten and actuate the fixation device (thereby extending thegrippers and rigidizing the flexible-to-rigid body, actuator 1408 istensioned by pulling in the direction of the arrow in FIG. 49 whilekeeping the rest of the device 1400 stationary. As it moves distally,ridges 1410 formed in actuator push against a cam surface 1412 formed incrown 1414 in ratchet 1417, expanding the crown enough to permit theridges to pass through. After passing through the crown, surface 1420 ofridge 1410 meets a stop surface 1422 of ratchet crown 1414, therebypreventing proximal movement of actuator 1408 after it has beentensioned. After deployment of the fracture fixation device within afractured bone, the portion of actuator 1408 extending from the end ofthe device after suitable tensioning may be cut and removed. A tool (notshown) may be used to release the ratchet in the event fixation device1400 must be repositioned or removed.

FIGS. 51-52 show yet another embodiment of a fracture fixation device1500 similar to that of FIGS. 49-50. Flexible body has two concentrictubular members 1506A and 1506B with opposing clockwise/counterclockwisehelical cuts. In order to rigidize flexible body 506 and deploy gripper1502, actuator 1508 is tensioned in the direction of Arrow A in FIG. 51.As it moves in that direction, ridges 1510 of actuator 1508 move againstcam surfaces 1512 of ratchet members 1514, which rotate outwardly aroundpins 1516. The interaction of face 1518 of ridge 1510 with face 1520 ofratchet member 1514 prevents actuator 1508 from moving back thedirection it came. The actuator 1508 may be released from the ratchet byusing a tool (not shown) to move the ratchet members 1514 to theposition shown in FIG. 52.

FIGS. 53-59 show alternative designs for the flexible body of a fracturefixation device according to this invention. FIGS. 53 and 54 showhelical wavy cuts formed in the flexible-to-rigid body so that it isflexible when not compressed and rigid when foreshortened andcompressed. FIG. 55 shows a canted helical wavy cut formed in theflexible-to-rigid body. FIGS. 56 and 57 show canted angles formed in thehelical cuts of the flexible-to-rigid body. FIGS. 58 and 59 show ahelical cut to form the flexible-to-rigid body. As in the earlierembodiments, the shape of the helical turns enables the transmission ofbending and torque along the flexible-to-rigid body, in addition to therigidizing function the body performs.

FIGS. 10 a-10 b, 11 a-11 b and 12 show an alternative embodiment of afracture fixation device 1600 according to aspects of the invention. InFIGS. 10 a-10 b, device 1600 is shown in a retracted state, and in FIGS.11 a-11 b and FIG. 12, device 1600 is shown in a deployed state. Likesome earlier embodiments, fixation device 1600 has a hub 1602, grippers1604 and 1606 and a flexible-to-rigid body 1608. Grippers 1604 and 1606may be constructed in a manner similar to gripper 1070 shown in FIGS.13-15 and described above. One or more additional flexible-to-rigid bodysections may be used, such as section 1610 located between gripper 1604and nose cone 1612 as shown. A threaded actuator 1614 extends throughthe device to threadably engage nose cone 1612. A rotational toolengagement portion 1616 may be provided on the hub end of the actuator bto rotate the actuator.

After device 1600 is inserted in place within an intramedullary space ofa fractured bone and spanning a fracture site, actuator 1614 may berotated with a tool inserted in portion 1616. As actuator 1614 isrotated, threaded nose cone 1612 travels distally with respect to thegrippers and the flexible-to-rigid components while hub 1602 remainsstationary. This action foreshortens device 1600 to deploy grippers 1604and 1606 and to rigidize components 1608 and 1610. When deployed to theconfiguration shown in FIGS. 11 a-11 b and FIG. 12, grippers 1604 and1606 tilt outward to dig their tips into the interior surface of thebone. To reposition or remove device 1600 from the bone, the actuatormay be rotated in the other direction to release the grippers and topermit the flexible-to-rigid components to become flexible again.

FIGS. 60 a-60 b and 61 a-61 b show an alternative embodiment of afracture fixation device 1700 according to aspects of the invention. InFIGS. 60 a-60 b, device 1700 is shown in a retracted state, and in FIGS.61 a-61 b, device 1700 is shown in a deployed state. Like some earlierembodiments, fixation device 1700 has a hub 1702, grippers 1704 and 1706and a flexible-to-rigid body 1708. Gripper 1704 may be constructed in amanner similar to gripper 1070 shown in FIGS. 13-15 and described above.Tripod gripper 1706 may be constructed in a manner similar to gripper1104 shown in FIGS. 22-33 and described above. A threaded actuator 1714extends through the device to threadably engage nose cone 1712. Arotational tool engagement portion 1716 may be provided on the hub endof the actuator 1714 to rotate the actuator. A threaded cap 1717 may beprovided to close opening of hub 1702 after fixation of the fracture toprevent bone and tissue ingrowths. A stop element, such as ball 1718,may be crimped, welded or otherwise attached to the opposite end ofactuator 1714 to prevent the actuator from being turned so far in thegripper retraction direction that actuator 1714 disengages from nosecone 1712 and device 1700 comes apart, particularly after insertion intothe bone.

The bent tip of a safety wire 1720 may be engaged in the aligning holesof a pair of arms of gripper 1706 when in a retracted position, as shownin FIGS. 60 a-60 b. Such an arrangement can help ensure that tripodgripper 1706 does not prematurely deploy as device 1700 is beinginserted into a medullary canal. After device 1700 is inserted into themedullary canal, safety wire 1720 may be disengaged and removed.Actuator 1714 can then be rotated, drawing nose cone 1712 toward the hubend of device 1700 to actuate grippers 1704 and 1706 in a radiallyoutward direction, and compressing body section 1708 in an axialdirection to change it from a flexible state to a rigid state aspreviously described.

FIGS. 62 a and 62 b shown an alternative gripper design embodiment,similar to gripper 1070 shown in FIGS. 13-15 and described above, foruse with, e.g., the fracture fixation device embodiments describedabove. In this embodiment, gripper 1870 has two rotatable cams 1872 and1874. Cam 1874 is attached by pins 1873 and 1875 to cam arms 1892 and1893, respectively. Cam arms 1892 and 1893 attach by pins 1894 and 1895to flanges 1882 and 1880, respectively. Similarly, cam 1872 is attachedby pins 1890 and 1891 to cam arms 1876 and 1878, respectively. Cam arms1876 and 1878 attach by pins 1877 and 1879 to flanges 1880 and 1882,respectively. Pins 1873, 1875, 1877, 1879, 1890, 1891, 1894 and 1895 maybe fabricated longer than necessary to ease assembly of gripper 1870.Each pin can include a stress concentration 1896 so that once the pin isinserted in its proper position and held in place by a press fit,welding or other means, the excess portion of the pin may be snappedoff. Flanges 1880 and 1882 connect with the components on either end ofthe device.

In an undeployed configuration, cams 1872 and 1874 are oriented suchthat the sharp tips 1885 and 1887 of cam 1872 and the sharp tips 1881and 1883 of cam 1874 do not extend from the cylinder of the gripper.When foreshortened during deployment, however, movement of flanges 1880and 1882 toward each other causes cam arms 1876 and 1878 to rotate aboutpins 1877 and 1879 with respect to flanges 1880 and 1882 and causes cam1872 to rotate about pins 1890 and 1891 with respect to cam arms 1876and 1878 so that the sharp tips swing out from the cylinder of thegripper, as shown in FIG. 62 a. Similarly, movement of flanges 1880 and1882 toward each other causes cam arms 1892 and 1893 to rotate aboutpins 1894 and 1895 with respect to flanges 1882 and 1880 and causes cam1874 to rotate about pins 1873 and 1875 with respect to cam arms 1892and 1893 so that the sharp tips swing out from the cylinder of thegripper, as also shown in FIG. 62 a. Thus, when part of a fracturefixation device has been inserted into a bone, deployment of the gripper1870 causes the sharp tips of the cams to dig into the bone to anchorthe device. It should be noted that unlike cams 1072 and 1074 of gripper1070 shown in FIGS. 13-15, cams 1872 and 1874 of gripper 1870 shown inFIGS. 62 a-62 b rotate in opposite directions when deployed. It shouldalso be noted that in all embodiments disclosed herein, in the event ofinadvertent breakage of an actuator or other component, the grippers areconfigured to nonetheless be able to return to a retracted position sothat the device may be removed from its implanted position in the bone.

FIG. 63 shows an embodiment of an outrigger tool 800. The outrigger 800allows precise placement of ancillary devices to the primary implant. Anancillary device includes a K-wire, screw, biological matrix, allograft,therapeutic, and or other material to aid in bone reconstruction. Theoutrigger provides a datum that acts as an interface to the primarydatum of the primary implant. As such, the outrigger sets the coordinatesystem for placement of ancillary material. In the case of a bone screwor K-wire, the outrigger ensures the bone screw creates a bone, implantbone interface and prevents interference or destruction of importantsoft tissue. In the case of a bone screw for the distal radius, theoutrigger ensures the bone screw attaches bone to the hub of the implantand further ensures that the screw cannot penetrate the radial ulnarjoint or the epiphysis. In the case of the placement of biologicalmatrices, osteogenic protein can be placed at the fracture site usingthe outrigger and x-ray guidance. In the case of therapeutic materials,the outrigger allows precise positioning of these materials for maximumeffectiveness. The outrigger has an interface to the implant that iseasily attached and removed by the surgeon. In one embodiment theattachment is a threaded collar, another embodiment includes a bayonet,and yet another embodiment includes a cantilever snap fit. Once attachedto the implant the outrigger and implant form an integral unitaryconstruction. The outrigger can be used to push and pull the implantinto and out of the intramedullary canal. The outrigger can serve as aninterface to drive the implant into the intramedullary space with akinetic energy device such as a hammer. The outrigger has an orificethat accommodates a guidewire or ratcheting guidewire. The outrigger canhave an implement that applies a relative force in the oppositedirection of the patient on the guidewire or ratcheting guidewire. Assuch the guidewire is pulled out of the patient and in the case of theratcheting guidewire, the implant is expanded and the implant forms asecure attachment to the diaphyseal bone. The outrigger can be used witha variety of hubs. The outrigger can be used with a variety of bonerepair device designs and does not need to be self-locking Thebone-device-bone interface enables it to stay in position.

Outrigger 800 has a connector portion 810 that connects to the hub andenables drilling through bone into the hub of the target implant, suchas those described above. In this embodiment, thumbscrew 820 is used tosecure the hub to connector portion 810. A feature of the outrigger isthat it enables drilling holes into the center of the hub withoutvisualization. Additionally, the sliding drill hole member on theoutrigger allows a large variation of angles that cross the hub. As willbe appreciated by those skilled in the art, the optimal angle will beeffected by the geometry of the broken bone to be repaired. After thestarter screw hole is dilled in the bone, the drill is removed and ascrew is inserted into the same outrigger hole, thereby guiding thescrew to the starter-hole in the bone.

While preferred embodiments of the present invention have been shown anddescribed herein, it will be obvious to those skilled in the art thatsuch embodiments are provided by way of example only. Numerousvariations, changes, and substitutions will now occur to those skilledin the art without departing from the invention. It should be understoodthat various alternatives to the embodiments of the invention describedherein may be employed in practicing the invention.

What is claimed is:
 1. A method of repairing a fracture of a long bone,the method comprising: advancing a bone fixation device across afracture of an intramedullary space of a long bone, wherein the bonefixation device comprises a rigid hub, a plurality of gripper elements,and an elongate body, wherein the rigid hub comprises a first end and asecond end and the rigid hub is advanced to a position spanning thefracture; operating an actuator from the second end of the rigid hub soas to inhibit movement of the elongate body; and deploying the pluralityof gripper elements of the bone fixation device from an advancementconfiguration to a deployed configuration extending radially outwardlyfrom the elongate body so as to engage an inner surface of theintramedullary space to anchor the bone fixation device to the longbone, further comprising inserting a screw into the bone on one side ofthe fracture and through the rigid hub so that, when implanted, thegripper elements and the screw affix the bone fixation device to thebone on the one side of the fracture, wherein the step of advancing abone fixation device is performed while the rigid hub has a preformedbore, the step of inserting a screw comprising inserting the screwthrough the bone and the preformed bore, wherein the rigid hub has aplurality of preformed holes, the method comprising inserting a firstscrew dorsal to volar through two portions of the bone and a first andsecond of the preformed holes and inserting a second screw volar todorsal through two other portions of the bone and a third and fourth ofthe preformed holes.
 2. The method of claim 1 wherein the operating stepcomprises rotating the actuator with respect to the bone fixationdevice.
 3. The method of claim 1 wherein the operating step comprisespivoting at least one of the plurality of gripper elements away from alongitudinal axis of the elongate body.
 4. The method of claim 3 whereinthe operating step comprises pivoting at least two of the plurality ofgripper elements away from the longitudinal axis of the elongate body.5. The method of claim 3 wherein the pivoting step comprises moving atleast two bone engaging surfaces of the plurality of gripper elementsinto engagement with the bone.
 6. The method of claim 3 wherein thepivoting step comprises moving at least three of the plurality ofgripper elements away from the longitudinal axis of the elongate body,the at least three of the plurality of gripper elements being disposedcircumferentially around the elongate body at the same axial position.7. The method of claim 3 wherein the pivoting step comprises pivoting apair of the plurality of gripper elements disposed on opposite sides ofthe elongate body at the same axial position so that two surfaces ofeach of the gripper elements engage the inner surface of theintramedullary space.
 8. The method of claim 7 wherein the pivoting stepcomprises rotating the plurality of gripper elements in a firstdirection.
 9. The method of claim 1 wherein the long bone is any one ofthe group consisting of a radius, ulna, humerus, clavicle, femur, tibia,and fibula.
 10. The method of claim 1 further comprising forming a borethrough the bone prior to inserting the screw.
 11. The method of claim 1further comprising inserting a third screw proximal to distal throughtwo more portions of the bone and fifth and sixth of the preformed holesof the hub.
 12. The method of claim 1 further comprising attaching adrill alignment guide to the rigid hub and aligning a drill bit with thehub using the drill alignment guide, wherein the screw is inserted inthe bone using a hole in the bone drilled with the aligned drill bit.13. The method of claim 1 wherein advancing the bone fixation deviceinto the intramedullary space of the bone comprises the use of aguidewire.
 14. The method of claim 13 wherein the guidewire is used toguide tools in preparing the intramedullary space of the bone prior toadvancing the bone fixation device.
 15. The method of claim 1, whereinthe fixation device is inserted into an opening in a second portion ofthe bone, wherein the elongate body of the fixation device comprises atubular body having a generally helical cut, the generally helical cutfacilitating flexing along the elongate body when the elongate body isinserted into the intramedullary space through the opening; thegenerally helical cut defining a wave superimposed on a helical cutalong a circumferential turn of the generally helical cut, the waveengaging an adjacent circumferential turn of the generally helical cutso as to transmit torque along the elongate body; and wherein the methodfurther comprises rigidizing the elongate body from a flexible state toa rigid state by imposing an axial load on the tubular body in responseto rotating the actuator about an axis of the rigid hub so as to inhibitaxial flexing along the tubular body.
 16. The method of claim 1, whereinthe fixation device is inserted into an opening in a second portion ofthe bone, wherein the elongate body of the fixation device comprises atubular body having a plurality of segments, the plurality of segmentsfacilitating flexing along the elongate body when the elongate body isinserted into the intramedullary space through the opening; theplurality of segments configured to transmit torque along the elongatebody; and wherein the method further comprises rigidizing the elongatebody from a flexible state to a rigid state by imposing an axial load onthe tubular body in response to rotating the actuator about an axis ofthe rigid hub so as to inhibit flexing along the tubular body.